check engine light question

[Poooobaa]

One of my 318is cars is throwing a check engine light between on and off the throttle. Also a 1222 dme code. Car runs great under all conditions. It did start this after a 3 mile hyper mileage coast. Don't know if this caused anything. Basically the car is in perfect tune with all parts needed - done.
Any input for me would be greatly appreciated.

[EN318isPDX]

all parts needed - done.

You can't expect input when you don't tell us what you've done to fix it? I'd guess o2 sensor or TPS

[Matt-B]

tps makes idle shitty, guessing o2

[Matt-B]

your welcome


1222 - Lambda control fault code is produced when Motronic system in Bosch control unit receives signal indicating that air/fuel mixture is either excessively rich or excessively lean for period of time loner then 10 seconds. Majority of the causes that affect drivability of the car can be responsible for DME flashing this error:
air leak
defective Air Flow Meter ( AFM)
bad engine temperature sensor
incorrect fuel pressure
problem with injector(s)
defective evaporation system
empty gas tank
issue with spark plugs
problem with valves
etc.

[Jimmy Lewis]

I would start by running the car and noting how it runs, then pull the connector for the o2 sensor and see if it runs any worse. It shouldn't be super noticeable but I could tell on my car between a bad sensor and a good sensor fairly easily. That would be a good way to start troubleshooting, and its free. I would also pull the AFM and make sure it is absolutely clean. Make sure all of the plugs look good, and it may be a good idea to pull them after running for a short time and see if they smell like fuel. Its more than likely a simple vacuum leak though, because it flashes on and off throttle, when the car is seeing vacuum on and off.

[quinn11m20]

The same thing happened to me years ago it was because of a vacuum leak. Under further inspection all the hoses under the intake were replaced. That stopped the check engine signal.

[Poooobaa]

Good input - Thanks. So after sitting in the garage overnight and cooling, it showed no sign of the problem when i drove it today until I was able to go 80 for 5 miles on an interstate. Got it again. Same deal. On throttle brought the CEL on and off throttle it went off. Plugs and injectors are new. All hoses and vacuum lines are new. Mess under the intake is done. Pulled and inspected plugs today. They look great. I was told the O2 sensor was done but that is still a possibility I guess. The car never even hiccups, just pulls strong even with the ac on. So I slow down and get on a side street. 2 minutes and no problem. I am getting ready for a road trip in this car or I wouldn't really care.

[Poooobaa]

Replaced o2 sensor today. So far - problem solved. Plus the car is a little stronger.